Here is the situation. I currently have a DIY sonosub that I built using a Dayton 15" Titanic MK3 and 1000 watt Dayton plate amp. The sub is in a 36 inch diameter sonotube, 30 inches tall with 2 - 4" ports which are each 11 inches long- if memory serves me. I believe tuning frequency is somewhere in the 14-16 hz range. It's been a while since I looked at the build calculations. The sub so far has been great and performs well. However, it does occupy a great deal of real estate in the living room and guests constantly ask why I have the world's largest empty spool of thread in the corner.

I am contemplating building 2 much smaller subs using the Infinity 1262w driver. As other builds have highlighted, they are cheap, I have one in my car that I have been very impressed with, and they seem to be well built with fairly good specs. I would be running 2 of these drivers in a sealed 3 cubic foot cabinet and running 2 subs total = 4 drivers. I would probably just sell the sonosub and amp.

My question is: Will I achieve any noticeable improvement in sound quality and or quantity with this setup as compared to what I have now? I realize I may not get the extension compared to what I currently have but this is going to be a 95% home theater setup and very little music. I am willing to sacrifice some of the ultra lows for a higher W.A.F. and what I hope will be an improvement in sound quality. If I do this, I would also welcome any recommendations for a good inexpensive pro amp to drive both subs. Any comments or suggestions would be welcomed.

That was part of the motivation. I have fooled around with REW in the past and I did everything right but was unable to really dial in the sound that I wanted. I am looking for an accurate and tightly controlled low end with a lot of reserve available... if that makes sense?

Depending on where you place the two new subs, and your room, it could pretty much be as good as it gets on bass evenness. Gotta be better than one 15" regardless.

One thing, though. If you have the power available, you can build the boxes a lot smaller than the 1.2cu ft/driver quoted. One example is 0.7cu ft/driver for the 1260W, which gives Qtc=0.76 vs 0.59 for 1.2cu ft. Especially with REW and eq available, the difference in FR will be negligible. Real difference will be in power required to hit xmax at 20Hz, which is still reasonable at roughly 300W/driver vs. 150W/driver for the bigger box. Haven't checked, but likely similar story for 1262W.

I would likely be corner loading both of them in opposing diagonal corners. The room is very large, 20X20 with 12 foot vaulted cielings and a 14 foot wide opening into the room. I figured by placing them in opposing corners, I would get the most from potential room gain and equalize out the bad spots using REW.

So you are going from a Dayton titanic 15 in a large ported Sonotube, and now your are going to 2 Infinity 1260's, and you are expecting a better home theater performer? I may be wrong, but I seriously doubt you are going to get better sq with 2 sealed lesser quality drivers.

With 4x 1260w you should have plenty of output. Not building rockets with winISD but to me it hits 100dB by 12Hz going on into the 120s topping at about 124dB at 50Hz. Impressive for just over $200 in drivers if you ask me.

"I should really see what dB levels I'm pushing. Long as it can't foam my beer during a movie we are ok "

So you are going from a Dayton titanic 15 in a large ported Sonotube, and now your are going to 2 Infinity 1260's, and you are expecting a better home theater performer? I may be wrong, but I seriously doubt you are going to get better sq with 2 sealed lesser quality drivers.